Global estimates of modern slavery: Forced labour and forced marriage - Methodology

The Methodology report of the “2022 Global Estimates of Modern Slavery: Forced Labour and Forced Marriage” presents the rigorous statistical framework underpinning the most comprehensive global estimates to date. Jointly developed by the International Labour Organization (ILO), Walk Free, and the International Organization for Migration (IOM), this methodological report details how data were collected, analysed, and validated to produce credible, policy-relevant figures on modern slavery.

Building on previous editions, the methodology reflects significant advances in measurement techniques, including the use of nationally representative household surveys in 68 countries, innovative modelling approaches, and integration of administrative data from the Counter-Trafficking Data Collaborative (CTDC). It also incorporates the latest international statistical standards, such as the ILO Guidelines concerning the measurement of forced labour, endorsed by the 20th International Conference of Labour Statisticians (ICLS).

The report outlines how forced labour — including forced labour exploitation, forced commercial sexual exploitation, and state-imposed forced labour — and forced marriage were measured across diverse contexts. It also addresses key challenges such as underreporting, ethical considerations, and the impact of the COVID-19 pandemic on data collection and prevalence.

By providing transparency on the estimation process, this methodology report supports the credibility and replicability of the global estimates. It is an essential resource for researchers, policymakers, and practitioners working to eliminate modern slavery and promote decent work for all.